Treatment Of Brain AVMs (TOBAS) trial is online

Centre hospitalier de l'Université de Montréal (CHUM)

MedSciNet has launched the online database for the Treatment Of Brain AVMs (TOBAS) trial, operated by the Centre hospitalier de l'Université de Montréal (CHUM). It is a pragmatic, prospective, multicenter, randomized, controlled trial and registry, which offers a care trial context for brain arteriovenous malformation (AVM) patients, including surgical resection, radiosurgery or endovascular embolization, alone or combined. Patient recruitment is under-way.

Cerebral AVMs are complex, heterogeneous, uncommon lesions that can lead to significant neurological disability or death, most commonly from intracranial hemorrhage. Intracranial AVMs are typically diagnosed before the age of 40, approximately 40–50 % with a hemorrhagic presentation. An AVM-related seizure is reported as the presenting feature in 20–35 % of cases and although these can be successfully managed with anti-epileptic agents, some AVMs lead to intractable seizures in spite of medication. Other presentations include headaches or focal neurological deficits. AVMs can also be incidental findings during investigation of unrelated symptoms. Population-based data suggest that the annual incidence of discovery of a symptomatic AVM is approximately 1 per 100,000 population.

The management of brain AVMs is controversial and complex. Three different modalities are currently used (surgical resection; endovascular embolization; radiotherapy) alone or in various combinations, depending on local expertise, size, location of the lesion, and clinical presentation. As the management options have evolved, individual and combined modality treatment protocols have developed in various directions in different institutions. The choice of management is largely dependent on the decisions of the local physicians that make up the treatment team, and a recent survey has demonstrated substantial variability in decision-making for almost all types of AVMs.

The general objective of the TOBAS trial is to offer a care trial context for the management of patients with brain AVMs (ruptured or unruptured). Two randomized studies will be performed with the following primary objectives:

1) To compare the effect of conservative versus interventional management (i.e. neurosurgery, radiosurgery, embolization, alone or combined) on a composite of disabling stroke or death from any cause at 10 years in patients with unruptured AVMs (patients with ruptured AVMs will be analyzed separately in secondary analyses).

2) To compare the effects of embolization prior to neurosurgery or radiotherapy versus neurosurgery or radiotherapy alone, in the management of patients with ruptured or unruptured AVMs, on a composite outcome of complete obliteration of the AVM combined with an independent functional outcome at the end of the management plan.

More information about the TOBAS trial can be found here